This invention relates to a method and apparatus for attaching a connection terminal to an electric wire having an insulation coating thereon, such as a plastic or rubber-coated cable.
The conventional way to tightly secure a connection terminal to an end of an electric wire having an insulation coating involves cutting and removing the coating for a predetermined distance from the end of the insulated wire by means of a knife or a wire stripper, inserting the bared wire into a tubular cylindrical portion of the connection terminal, crimping tightly the cylindrical portion by the use of pliers or the like and, if necessary, covering the cylindrical portion of the connection terminal and the electric wire with an insulating tube of the heat-shrinkable type or with an insulating tape. In such case, while it is necessary to cut the insulation coating from the end of the wire, it is disadvantageous because the core wire may often be impaired. Many improvements in this regard have been proposed in the construction of wire strippers, which improvements were however incomplete because they did not face the difficulty of inserting the core wire inside the hole of the cylindrical portion of the connection terminal when part of the insulation remains or when the core wire is shifted or deformed. Thus, installation of the connection terminal has not been fully simplified.
Some approaches to permit installation of the connection terminal without cutting the insulation have been made by moving the portion of the insulation coating at the end of the wire so as to expose the core wire. Those approaches generally include means for fastening the electric wire and means slidable with respect to the fastening means for gripping the insulation coating, whereby the insulation is so moved backwardly with respect to the core wire as to expose the end of the core wire. However, smooth relative movements are difficult to attain between the core wire and the coating, and the apparatus for gripping and sliding the coating is bulky and of large size. Another serious problem is that the connection terminal has to be conveyed to another location for installation on the core wire after the wire has been bared.